Abstract: An electrostatic display device has a closed opaque chamber with one or more transparent windows in a side thereof. Mounted within the chamber adjacent to each window is a resilient electrode that is capable of moving so as to block the adjacent window or to withdraw from the window in response to a signal voltage that is applied between the resilient electrode and a fixed electrode. The total window area is less than about 20% of the exterior surface area of the chamber so that an "open" window functions optically as a light sink and appears dark. The outer surface of the resilient electrode may be of a bright hue for optical contrast in a normally bright "day time" ambient. Alternatively a lamp within the chamber provides an electrically actuated display that is visible in a dark ambient.

Abstract: In an electrostatic device for the gating of electromagnetic radiation in response to an electrical signal, including a fixed and a resilient variable electrode with a film of insulation interposed therebetween, the variable electrode lies adjacent to the fixed electrode defining a line of tangency therebetween. The position of mounting of the variable electrode is spaced from the line of tangency and in this space the variable electrode has a curved portion that minimizes wrinkles therein and provides a lower and more predictable sensitivity. Furthermore, the assembly of such devices tends to become less critical and simpler.

Abstract: An electrostatic device includes a fixed electrode to which is attached an end edge of a coiled or curved variable resilient sheet electrode. An insulative layer separates the two electrodes, being either bonded to the fixed electrode or being bonded to the resilient electrode. The resilient variable electrode is caused to unroll upon the application of an electric potential between the two electrodes. The device is particularly adaptable for use as a light gate. It is capable of being actuated by an electrical potential either in a light transmission mode or in a variable reflectivity mode.